919糖浆抗鸭乙型肝炎病毒的实验研究

目的:研究919糖浆时鸭乙型肝炎的体内抗病毒作用。方法:以感染鸭乙型肝炎病毒(DHBV)的武汉麻鸭为实验动物模型。使1d龄武汉麻鸭感染DHBV,7d后用Dot-EIA法筛选出DHBsAg强阳性鸭。随机分组后给予919糖浆治疗14d,于感染后第7d(为用药前)、用药7d、14d及停药后3d分别采血,采用斑点杂交方法检测血清DHBVDNA。结果。用药919糖浆7d、14d鸭血清DHBV DNA OD值均明显低于给药前,有显著性差异(P<0.05,P<0.01)。停药3d后没有反跳现象。结论:919糖浆有一定的抑制DHBV DNA复制作用。     

鸭乙型肝炎病毒体液免疫血清学指标的系统建立与应用

目的：建立简便,特异的鸭乙型肝炎病毒（DHBV）感染及免疫血清学检测系统。方法：制备、纯化检测所需同的抗DHVB前S区单克隆抗体腹水,DHBsAg和rDHBcAg , 对随机筛选的80份感染血清及实验感染1日龄重庆麻鸭系列血清分别进行DHBsAg 和抗－DHBc,抗－DHBs检测。结果：PCR方法检测出阳性66份,阴性14例,选用PCR阳性的66份标本,经HDBsAg ELISA检测出58份阳性,斑点杂交检出阳性份数为62份。与DHBVRCR相比较,灵敏度分别为87．9％和93．9％,而8只实验感染鸭仅2只在感染后第3周血清抗－DHBc阳性,抗体效价为1：10,至第4周一已为阴性,抗－DHBs则在所有标本均为阴性,结论：DHBV感染及免疫血清学酶联免疫方法的建立,为进一步研究DHBV感染后腹制规律及体风免疫应答状况奠定了基础。     

实时荧光定量PCR在手足口病肠道病毒快速检测中的应用

目的建立快速检测手足口病肠道病毒的实时荧光定量PCR法,并作出应用分析。方法采用卫生部《手足口病预防控制指南》(2008年版)推荐的RT-PCR法,对丽水市2008年4～5月间发生的172例临床诊断手足口病患者的324份标本进行人肠道病毒、柯萨奇病毒A组16型和肠道病毒EV71型特异性核酸的检测,同时采用实时荧光定量PCR法进行平行检测,比较两者的实验结果,分析实时荧光定量PCR方法的特异性和灵敏度。结果实时荧光定量PCR检测324份标本,肠道病毒通用核酸阳性70份,柯萨奇A16核酸阳性22份,肠道EV71病毒核酸阳性15份,与RT-PCR结果一致,符合率100%。结论实时荧光定量PCR法具有特异性强、灵敏度高等优点,是一种理想的手足口病肠道病毒的检测方法。     

乙型肝炎肝纤维化麻鸭球结膜微循环及血液流变学特点

目的:观察鸭乙型肝炎肝纤维化动物模型的球结膜微循环及血液流变学特点。方法:用鸭乙型肝炎病毒(DHBV)阳性血清反复攻击建立鸭乙型肝炎肝纤维化动物模型,并检测球结膜微循环、血液流变学指标,肝纤维化指标、肝脏病理组织学变化。结果:用DHBV反复攻击造模后,其病理组织学改变具有肝脏细胞炎症,肝纤维组织增生,血清肝纤维化指标升高(P<0.01),球结膜微循环明显障碍(P<0.01),血液流变学改变(P<0.01)。结论:乙型肝炎肝纤维化麻鸭具有明显的微循环障碍及血液流变学改变。     

实时荧光定量PCR在登革热病毒快速检测中的应用

目的应用实时荧光定量PCR快速检测登革热病毒感染。方法采集疑似登革热患者血清,采用实时荧光定量PCR检测登革热病毒,同时采用ELISA检测血清登革热IgM抗体。结果患者发病第7d血清登革热IgM血清抗体A值为0.236和0.237(临界值0.250),高度疑似阳性,第13d血清IgM抗体阳性。患者发病第2d,通用型核酸检测显示血清登革热病毒核酸含量较多,经过治疗,于第7d病毒拷贝下降。发病第2d,核酸检测确定感染病毒为登革热Ⅲ型;发病第13d血清登革Ⅲ型病毒核酸检测阴性。结论实时荧光定量PCR法具有准确性好、灵敏度高等优点,可用于登革热病毒感染的快速检测。     

乙型肝炎病毒共价闭合环状DNA套式-实时荧光定量聚合酶链反应的建立

目的 建立检测HBV共价闭合环状DNA(cccDNA)的套式一实时荧光定量PCR法.方法 根据HBV cccDNA与松环DNA(rcDNA)结构上的差异,设计2对跨缺口的特异引物及1条位于负链缺口下游的特异TaqMan荧光探针.根据Plasmid-SafeTM ATP-Dependent Dnasc(PSAD)对rcDNA与cccDNA作用的不同,对模板DNA进行酶切纯化,降解reDNA,再进行套式PCR扩增,先用外引物和模板进行第一轮常规PCR,再用内引物、荧光探针和第一轮PCR产物进行实时荧光定量PCR,根据阳性参照标准品,得出待检标本定量值.结果 检测阳性参照标准品.得出该方法灵敏度可达2 lg拷贝/mL.用上述方法检测34份乙型肝炎患者血清HBV DNA阳性标本,25份血清HBVcccDNA阳性,28份外周血单个核细胞HBV cccDNA阳性.27份健康对照者血清HBV DNA阴性标本,6份HBV cccDNA阳性.对5份HBV cccDNA阳性标本扩增产物进行克隆测序,无碱基缺失、突变.与HBV不同基因型序列(A～G)比较,同源性为90.6%～99.1%,其中,与B、C基因型同源性为95.3%～99.1%,验证了方法的特异度.结论 套式-实时定量PCR法可检测乙型肝炎患者血清、PBMC中的HBV CCCDNA,且具有敏感、特异性.     

鸭乙型肝炎病毒对鸭心肌细胞超微结构的影响

将鸭乙型肝炎病毒(DHBV)感染雏鸭制作的鸭乙型肝炎模型已被广泛用于研制抗乙肝病毒新药,为探索DHBV感染对雏鸭心脏有何影响,我们观察了被DHBV感染的雏鸭其心肌的超微结构,现报道如下。 1 材料与方法 1.1 动物及分组 20只1日龄武汉麻鸭(购自华中农业大学种禽厂),随机分为对照组和感染组,每组10只。 1.2 造模方法及标本制作 雏鸭喂养1周后,分成2组:感染组每只鸭自胫静脉注射DHBV阳性血清     

乙型肝炎病毒cccDNA巢式-实时荧光定量PCR法的建立及应用

目的建立检测HBV共价闭合环状（cccDNA）的巢式-荧光定量PCR法,检测外周血单核细胞（PBMC）及骨髓单核细胞（MMNC）中cccDNA。方法根据HBV cccDNA与松弛结构DNA（rcDNA）结构上的差异,设计2对跨缺口的特异性引物及下游的特异性TaqMan探针。根据Mung Bean Nuclease对rcDNA与cccDNA作用的不同,使cccDNA扩增而使rcDNA降解,分别用外引物及内引物进行PCR反应,再用荧光探针进行实时荧光定量PCR,根据阳性参照物,计算出检测标本定量值。结果成功建立了HBV cccDNA巢式-荧光定量PCR的检测方法,线性范围为5.0×102～3.9×107拷贝/ml。用上述方法检测25例慢性乙型肝炎（CHB）及肝硬化血清HBV DNA阳性患者PBMC中cccDNA,7例MMNC中cccDNA,21例健康献血者PBMC cccDNA,骨髓标本中有3例cccDNA阳性,25例外周血标本中有9例cccDNA阳性。结论巢式-荧光定量PCR法可检测乙型肝炎患者PBMC及MMNC中的HBV cccDNA含量。PBMC及MMNC中可检测到HBV cccDNA。     

基于GroEL基因的实时荧光定量PCR检测恙虫病东方体方法的建立及评价

目的 建立一种敏感、特异的实时荧光定量PCR方法,用于检测临床标本中的恙虫病东方体。方法 根据恙虫病东方体GroEL蛋白基因序列设计引物和探针,建立实时荧光定量PCR检测方法。并从灵敏度、特异度、重复性及临床标本的检测能力等方面对本方法进行综合评价。结果 建立的实时荧光定量PCR方法具有良好的特异性,可检测出恙虫病东方体Gilliam、Karp、Kato和Kawasaki株。建立的标准曲线循环阈值(Ct)与模板拷贝数呈现良好的线性关系(r=0.99),灵敏度分析显示样品最低检出浓度为21.8拷贝/μL。批内及批间重复性实验变异系数均小于1.5%,显示本方法具有良好的重复性。对本实验室保存的82份临床标本进行检测,并与常规巢式PCR方法比较,本方法检测出26份阳性标本中的25份,检出率为96.15%。结论 本研究建立的实时荧光定量PCR方法具有较高的敏感性、特异性和稳定性,可用于临床病人及暴发疫情的实验室快速检测。     

输血传播病毒PCR-DHPLC检测技术的建立及初步应用

目的应用聚合酶链式反应(PCR)结合变性高效液相色谱(DHPLC)技术检测输血传播病毒。方法根据输血传播病毒的核酸序列特点设计特异性引物进行PCR,将扩增产物进行DHPLC检测分析,以验证方法的灵敏度、特异性、重复性,同时进行临床检测的初步应用。结果以乙型肝炎病毒、丙型肝炎病毒、戊型肝炎病毒进行特异性试验,无交叉反应,具有较好的特异性;重复性良好;灵敏度可达1.0×10~1拷贝/反应。分别应用实时荧光PCR法、普通PCR法及本文所建立的PCR-DHPLC法同时检测32份血清样本,发现有17份样本实时荧光PCR阳性,17份样本PCR-DHPLC阳性,15份普通PCR阳性。结论本文建立的PCR-DHPLC法具有特异、敏感、重复性好等优点,可用于输血传播病毒感染的分子流行病学调查。     

Studies on duck hepatitis B virus: Identification and epidemiological survey in Taiwan

The presence of duck hepatitis B virus (DHBV) in domestic ducks in Taiwan was confirmed by DNA polymerase assay, Southern blot analysis and electron microscopy. To investigate the epidemiology of this virus, a total of 1274 serum samples were collected from 30 duck farms from different areas of Taiwan and studied by spot hybridization and/or DNA polymerase assay. The positive rates varied among different strains of ducks: 16% in 243 Pekin ducks, 12% in 392 Chinese common domestic ducks, 4% in 196 Muscovy, 25% in 292 Taiwan Kaiyas and 13% in 151 mule ducks. The positive rate was much higher in the younger ducks; it was highest (30.7%) in ducklings under 1 month of age, followed by ducks aged 1–12 months (11.8%), and lowest in those ducks older than 1 year (7.7%). It was concluded that the prevalence of DHBV infection in domestic ducks in Taiwan is generally high, and that the infected ducks may serve as an animal model for human hepatitis B virus infection which is also prevalent in Taiwan.     

The relationship between duck hepatitis B virus infection and duck liver diseases in Qitong, China

The relationship between duck hepatitis B virus (DHBV) infection and duck liver diseases was analysed by spot and gel blot hybridization in sera and liver tissues. One hundred and forty ducks were obtained from Qitong county in China. The DHBV-infected rate was 65.7% and the incidence of duck liver diseases was 70%. The state of DHBV DNA was free in the hepatocytes. The detection rate of DHBV DNA in liver was higher than in serum. The results showed that Qitong duck liver diseases are closely correlated to DHBV infection. The incidence of Qitong duck liver diseases and the DHBV infection rate were different in various species of ducks. Qitong ducks have several hepatic pathological changes as seen in human beings. Therefore, Qitong ducks are most appropriate as an experimental model for human HBV infection.     

重庆麻鸭乙肝动物模型的建立及应用——21种中药抗鸭乙型肝炎病毒初筛研究

采用斑点杂交法检测了重庆地区263份2～3月龄麻鸭血清中的DHBV DNA,用筛选出的阳性病毒血清经腹腔感染1～2日龄的血清DHBV DNA阴性雏鸭,并用该模型进行了21种中药抗乙肝病毒初(?)。结果表明:(1)重庆地区2～3日龄麻鸭DHBV自然感染率为25.48％.(2)经腹腔感染的1～2日龄雏鸭的血清DHBV DNA阳性率1周后为82.90％,并可持续至少2个月。(3)抗乙肝病毒中药初(?)发现用广西叶下珠、苦参治疗2周可使DHBV DNA滴度下降,其余的经体外实验认为有效的抗乙肝病毒中药,动物实验并未获证实。     

Ampligen及其与Ganciclovir和Coumermycin Al联合应用对血清中鸭乙型肝炎病毒抑制效果

Ａｍｐｌｉｇｅｎ是一种免疫调节剂或干扰素诱导剂。单独和联合Ｇａｎｃｉｃｌｏｖｉｒ和／或ＣｏｕｍｅｒｍｙｃｉｎＡｌ治疗了鸭乙型肝炎病毒（ＤＨＢＶ）阳性鸭模型。结果表明,上述三种治疗方。案对鸭血清中ＤＨＢＶ均有抑制作用,但治疗结束ＤＨＢＶ回升到治疗前水平。任何一种方案对血清循环ＤＨＢＶ表面抗原（ＤＨＢｓＡｇ）均未产生明显抑制效果。本研究结果为人乙型肝炎治疗时合理使用抗病毒药物和免疫调节、诱导剂提供了重要参考。     

Enhanced duck hepatitis B virus gene expression following aflatoxin B1 exposure

Epidemiological studies have suggested synergistic interactions between chronic hepatitis B virus (HBV) infection and aflatoxin B1 (AFB1) exposure in the etiology of hepatocellular carcinoma (HCC), although the molecular mechanisms of their interactions are still not understood. The aim of this study was to use the Pekin duck model to investigate the impact of AFB1 exposure on duck hepatitis B virus (DHBV) replication during the early stages of virus-carcinogen interactions. Six-week-old chronic DHBV-carrier or uninfected ducks were exposed to AFB1 for 5 weeks or treated with dimethylsulfoxide (DMSO) as a control. Animals were observed for 6 to 13 weeks after AFB1 treatment to study the influence of AFB1 exposure on DHBV replication and liver pathologies. Histological analysis showed more marked changes in the livers of AFB1-treated ducks, and these were enhanced by DHBV infection. A significant increase in serum and liver DHBV DNA level was observed in AFB1-treated ducks as compared with DMSO-treated controls. In addition, viral RNAs, in particular the pregenomic RNA that is the template of viral replication, and intrahepatic DHBV DNA replicative intermediates, were significantly increased by AFB1 treatment. Moreover, an overexpression and accumulation of DHBV large envelope (L) protein was observed in the hepatocytes of AFB1-exposed animals. The in vitro study has further confirmed an increase in intracellular viral DNA and in virus release in AFB1-treated primary duck hepatocytes. Taken together, our results indicate that AFB1 exposure leads to an increase in virus gene expression associated with intrahepatic accumulation of DHBV L protein and enhanced liver pathology.     

Inflammation of the liver causes mutations in duck hepatitis B virus genome

To investigate whether hepatitis causes mutation in the viral genome, DNA sequences in the pre-core region of duck hepatitis B virus (DHBV) DNA were analyzed in both ducks with hepatitis and without hepatitis. Five DHBV carrier ducks were injected with DHBV particle proteins purified from duck serum with Freund’s complete adjuvant (FCA) intrahepatically from 14 day posthatch for 9 weeks (immunized group). Serum was drawn at the end of the 1st and 4th week after the 1st injection of DHBV particle protein and ducks were killed at the end of the 9th week to obtain the liver. Another five ducks without treatment were used as controls. All ducks of the immunized group showed moderate to severe hepatitis at the 9th week. All ducks in the immunized group showed one mutation except one duck that showed two mutations only at the 9th week. Mutations were observed in the 5th, 13th, 21st, 22nd, and 28th codon of the precore region. All of them were point mutation at the 3rd base in the triplets. The frequency of mutation was different in each duck from 20% to 60% but not 100%. There was no mutations in ducks in control group. These results suggest that hepatitis causes mutation in the pre-core lesion genome of duck hepatitis B virus.     

Replicative efficiency and pathogenicity of hepatitis B virus e-minus precore variant

Abstract To study the replicative efficiency and pathogenicity of hepatitis B virus precore variant (A1896), anti-hepatitis B virus e antigen (HBe) titre was studied in naturally occurring wild-type virus infection, A1896 variant infection and dual infection. Higher titre of anti-HBe was found in patients with no virus replication and in patients coinfected with the wild-type virus and A1896 variant, which suggest that anti-HBe may either act as an inhibitor of virus replication or as selective pressure for the A1896 variant. Three site-directed mutants were constructed in the duck hepatitis B virus (DHBV) precore region. A frame shift in the encapsidation signal region abolished replication of DHBV; mutation in the initiation codon of the precore and mutation to generate a termination codon at the distal region of the precore resulted in decreased replication in the duck model. More significant pathological changes were found in the liver tissues of ducks infected with the mutant which mimicked the HBV A1896 variant.     

Liver disease associated with duck hepatitis B virus infection of domestic ducks.

The liver disease associated with duck hepatitis B viremia was investigated in naturally infected ducks from Chi-tung county in China and in both naturally and experimentally infected ducks from the United States. Liver and serum specimens of adult Chinese ducks were examined for duck hepatitis B virus (DHBV) DNA by dot and gel blot hybridization. DHBV was found in serum and (in episomal form only) in livers of 6 of 11 birds exhibiting various degrees of chronic hepatitis. In 1 bird with hepatocellular carcinoma, DHBV DNA was detected at the limit of assay sensitivity and in another not at all, contrasting with findings in humans and woodchucks. In work with California Pekin and Khaki Campbell ducks, known amounts of DHBV were injected into the egg 10 days before, or into ducklings 1 day after, hatching and the livers were examined 6 weeks later. The majority of the injected ducklings had viremia detectable by hybridization 1 or 2 weeks after injection. The presence but not the amount of viremia correlated with incidence and degree of hepatitis, determined under code. The most severe instances of hepatitis, all in Pekin ducks, resembled the hepatitis in adult Chinese ducks of Chi-tung county. Severe and moderate hepatitis were found only in indoor-caged injected animals with viremia and in some uninjected birds without viremia that had been kept in outdoor flocks. The latter hepatitis, as some hepatitis in adult Chinese ducks, may not be related to DHBV. Mild and insignificant hepatitis were also found in injected and noninjected ducklings, some of which had the vertically transmitted spontaneous viremia previously described. The good correlation of experimentally induced viremia with incidence and severity of hepatitis in the Pekin duckling provides a simple, rapid, and relatively inexpensive model to study the relation of lesions to hepatitis B family infection in nonprimates.     

Duck hepatitis B virus and liver diseases

The presence of duck hepatitis B virus in serum was studied in 61 ducks (24 from Chi-tung county, China, 20 from Changchun, China, and 17 from Chiba, Japan) with relation to liver disease. None of the 37 ducks from Chiba and Changchun was positive for duck hepatitis B virus as assayed by electron microscopy, endogenous deoxyribonucleic acid-polymerase activity, and hybridization with duck hepatitis B virus deoxyribonucleic acid. No liver disease was seen in these ducks. In contrast, viruslike particles were present in the serum of 12 of 24 (50%) ducks from Chi-tung, China. The presence of duck hepatitis B virus in serum was indicated by the hybridization spot test and deoxyribonucleic acid-polymerase activities. A variety of liver diseases including chronic hepatitis and cirrhosis were seen in the livers of a majority of the ducks from Chi-tung. One duck hepatitis B virus-positive duck had multicentric hepatocellular carcinoma with underlying cirrhosis. Comparison of serum duck hepatitis B virus markers and liver disease in the affected flock revealed a tendency for seronegative ducks to have advanced liver diseases. Duck hepatitis B virus infection may be used as an experimental model to test various hypotheses concerning the pathogenesis of hepatitis B virus-associated liver disease in humans.